feat(admin): export tool for full migration / backup (#5294)

* feat: export content utility (wip)

* feat: export navigation + groups + users

* feat: export comments + navigation + pages + pages history + settings

* feat: export assets

server/core/kernel.js

@@ -106,7 +106,7 @@ module.exports = {
   /**
    * Graceful shutdown
    */
-  async shutdown () {
+  async shutdown (devMode = false) {
     if (WIKI.servers) {
       await WIKI.servers.stopServers()
     }
@@ -122,6 +122,8 @@ module.exports = {
     if (WIKI.asar) {
       await WIKI.asar.unload()
     }
-    process.exit(0)
+    if (!devMode) {
+      process.exit(0)
+    }
   }
 }